Week 12 / Pharmacology 2 Flashcards
Q: What are the 4 possible consequences of drug-receptor interactions?
Agonist
Antagonist
Allosteric modulator
Inverse Agonist
Q: What is an agonist drug?
A: An agonist drug mimics a natural, endogenous chemical messenger and produces the same effect.
Q: What is an antagonist drug?
A: An antagonist drug blocks the receptor and prevents the natural chemical messenger from binding, producing no effect.
Q: What is an allosteric modulator?
A: An allosteric modulator binds to a site near the binding site for the natural chemical messenger and influences its binding, producing either 1 or ½ the effect of the natural messenger.
Q: What is an inverse agonist drug?
A: An inverse agonist drug binds to the site normally occupied by a natural messenger and produces an opposite effect to the natural chemical messenger.
Q: What is the basic distinction between ‘Agonist’ and ‘Antagonist’ drugs?
A: Both agonist and antagonist drugs have affinity for their receptors, but agonists have efficacy, meaning they can activate the receptor and cause a biological response, whereas antagonists have no efficacy and block the receptor without producing a response.
Q: What is efficacy in relation to drug-receptor interactions?
A: Efficacy is a measure of the ability of the drug-receptor complex to transduce the drug binding into a biological response. It expresses the ability of the drug to activate the receptor and cause a conformational change that leads to a biological effect.
Q: What is affinity in relation to drug-receptor interactions?
How is it expressed?
A: Affinity is a measure of the ease with which a drug binds to its receptor, or the probability that the drug will interact with a receptor to form a drug-receptor complex. It is expressed by the equilibrium dissociation constant (K), where affinity = 1/K.
Q: Do agonists have efficacy?
A: Yes, agonists have efficacy. They are able to activate the receptor and cause a biological response.
Q: Do antagonists have efficacy?
A: No, antagonists have no efficacy. They bind to receptors but do not activate them or cause a biological response.
Q: What does a high efficacy value (e) indicate?
A: A high efficacy value (e) indicates that the drug is highly effective at activating the receptor and producing a significant biological response.
Q: What is an agonist drug?
A: An agonist is a drug that binds to its receptor, activates the receptor, and elicits a biological response.
Q: What are the two types of agonists?
A: The two types of agonists are:
Full agonist
Partial agonist
Q: What is a full agonist?
A: A full agonist is a drug that binds to its receptor and produces the maximum possible biological response that the receptor can elicit.
Q: What is a partial agonist?
A: A partial agonist is a drug that binds to its receptor but produces a less than maximum biological response, even when all receptors are occupied.